Things You'll Need
- Hobby-grade resin molding kit
- Knife
Instructions
Position the two trays from the kit beside one another. These trays are the two halves of the mold. If you intend to carve out your own mold shape, mix together the plaster included with the kit with water, fill the trays, and let it dry.
Mold a shape you already have by mixing the plaster mold with water and adding it to the molding trays. Press the front of the shape halfway into one of the trays, and the back of the shape halfway into the other tray. Let the trays dry.
Carve out the shape you want to mold in the plaster if you are molding your own design rather than producing a copy. The plaster mold material cuts easily with a knife, and some kits include these tools in their packaging. Carve the back side of the mold in the same spot as the front.
Carve a small access channel approximately the size of a drinking straw with the knife from the carving or impression to the top center of the plaster.
Put the two halves of the mold together. Wrap them with a strong rubber band or tie them with string so that they are pressed tightly together.
Mix the resin compound and the hardener. Immediately pour the mixture down the access channel you carved in the mold. Completely fill the mold until the channel itself is filled. Allow the resin to solidify for 20 to 30 minutes.
Open the mold and pull the design out. If necessary, break the plaster cast by smacking it sharply against a concrete floor. The resin won't break before the plaster does. Clean any excess plaster off the decoration.
Cut around the outside of the decoration with the knife to remove the resin that seeped into the cracks between the molds. Paint the decoration with aquarium-safe paint if you wish, or use it as it is.